How do I upgrade?

If your software supports 7.x, it can be as simple as upgrading the package on your server. Check out a guide for your specific operating system on how to do this. For example, here is how to do it for Ubuntu.

If your software contains 5.x-only features, you will need to update your software. Hiring a developer (or me) will allow you to get the benefits from the latest PHP version. The official website contains a guide on some of the things to look out for when migrating. Virtually all frameworks support PHP 7.x so upgrading is a matter of updating the glue code.

Unable to upgrade - Some hosting providers don't offer the ability to switch to 7.x.

"It works fine" - That may be true, but it doesn't stop the security vulnerabilities.

Why upgrade?

Performance

PHP 7.x ships using the PHPNG engine, giving drastic improvements in speed and CPU usage. This makes the whole site more responsive and search engines, like Google, use page speed in their ranking algorithm.

This has the potential to reduce server requirements, and therefore costs.

Security fixes

PHP doesn't have the best track record when it comes to security vulnerabilities. When a version reaches end of life status, it stops getting future security updates. This can present a risk to both yourself, and your users. All it takes is someone holding on to a 0-day exploit for everyone to have a very bad time.

New language features

Each minor version bump in PHP comes with new language features that allow for more terse, expressive code.